Bucket positioning kick-out controls for bucket loaders



Feb. 25, 1969 H. B. AUSTIN ET AL. 3,429,471

BUCKET POSITIONING KICK-OUT CONTROLS FOR BUCKET LOADERS Filed Sept. 8,1967 Sheet of 4 INVENTORS HOWARD B. AUSTIN JOHN D. WAIT, JR.

ATTORNEYS Feb. 25, 1969 H. B. AUSTIN ET AL 3,429,471

BUCKET POSITIONING KICK-OUT CONTROLS FOR BUCKET LOADERS Sheet Z of 4Filed Sept. 8. 1967 11-! 44 Ill/f; V I REL 42 43 v nzszvom J HEAD END orCYL.

ROD END OF CYL.

INVENTORS HOWARD B. AUSTIN JOHN D. WAIT, JR.

Feb. 25, 1969' H. B. AUSTIN ET AL 7 3,429,471

BUCKET POSITIONING KICK-OUT CONTROLS FOR BUCKET LOADERS Filed Sept. 8,1967 Sheet 3 M4 RESERVOIR I N VEN TORS HOWARD B. AUSTIN JOHN D. WAIT JRLATTORNEYS Feb. 25, 1969 H. B. AUSTIN ET AL 3,429,471

BUCKET POSITIONING KICK-OUT CONTROLS FOR BUCKET LOADERS Filed Sept. 8.1967 Sheet 4 of 4 INVENTORS HOWARD B. AUSTIN JOHN D. WAIT, JR.

United States Patent Office 3,429,471 Patented Feb. 25, 1969 Filed Sept.8, 1967, Ser. No. 666,292 U.S. Cl. 214-762 10 Claims Int. Cl. E02f 3/86,3/87 ABSTRACT OF THE DISCLOSURE Automatic stops associated with a bucketpivotally supported by the lift arms of a bucket loader for positioningthe bucket at four predetermined positions including dump, load dumpheight and ground or load level. The bucket loader has hydraulic jacksfor controlling bucket elevation and additional jacks for controllingbucket tilt which take precedence over the elevating jacks. Twokick-outs return the elevating jack to a hold position when the bucketis at dump height or ground level. Two additional kick-outs return thetilting jacks to hold when the bucket is suitably positoned for dumpingor filling. One of the kick-outs associated with each of the elevatingjacks and the tilt jacks is collapsible to prevent their functioningduring certain portions of the bucket loading operation.

Cross-reference to related U.S. patents U.S. Patent 3,211,310 entitled,Trip Mechanism for Automatically Positioning Vehicle Loaders, issued toR. G. McIndoo and assigned to the assignee of the present invention.

Background of the invention During operation of a bucket loader, itsbucket must assume various tilted positions as well as various positionsof elevation. The necessity of the operator to manually control the tiltand elevation positions of the bucket as Well as the operation of thebucket loader vehicle itself noticeably curtails the optimum operatingefiiciency of the unit. Increasing the size of the bucket loader toprovide a larger capacity not only increases these manipulative duties,but reduces the optimum operating efiiciency for other reasons as Well.For example, as the unit becomes larger it becomes more difficult forthe operator to exactly judge the various positons at which motion ofthe bucket is to be halted. If contact of the buckets with mechanicalstops or the ground is relied upon to limit bucket motion, contactingshock, particularly of large capacity buckets, is transmitted throughthe vehicle to result in undue mechanical wear to the loader as well asoperator fatigue.

Various solutions have been employed in the prior art to at leastpartially overcome these problems. For example, in U.S. Patent3,211,310, the bucket lift controls were provided with detents and withkick-outs disposed on the bucket lift arms to terminate operation of thebucket lift controls with the bucket at a selected dumping height or atground level for loading. However, as will be made more apparent in thefollowing description, such controls provide only a partial solution ofthe problem since the manipulative duties of the operator still includethe Operation of the vehicle as well as complete control over the tiltposition of the bucket.

The present invention overcomes the above problems by providing a bucketloader with a bucket positioning kick-out system which stops motion ofthe bucket preferably in four predetermined positions; namely, the dump,load, dump-height and ground level position.

The invention is described below with reference to the drawings wherein:

FIG. 1 is a side elevation of the forward portion of a bucket loader;

FIG. 2 is a schematic illustration of a control system for operatinghydraulic lift jacks associated with the bucket lift arms and kick-outswhich co-operate with the control to limit lift jack operation;

FIG, 3 is .a schematic illustration of a control system for operatinghydraulic tilt jacks and kick-outs which cooperate with the controlsystem to limit tilt jack operation;

FIG. 4 is a partial side view in elevation with parts in section of amaster valve which functions together with the bucket tilt kick-out; and

FIG. 5 is a sectioned view of a collapsible kick-out assembly forlimiting motion of the bucket lift-arms.

Referring now to FIG. 1, a bucket loader vehicle is illustrated ashaving a bucket assembly 12 pivotally connected thereto by means of apair of forwardly extending lift-arms, one of which is indicated at 13.Tilt linkage for controlling the tilt position of the bucket isgenerally indicated at 14 and comprises a forward lever 16 pivotallyconnected to each lift arm at 17 and to the bucket by means of a link18. A bell crank member 19 is pivotally connected at 21 to a rearwardportion of each lift arm and has its lower end 22 pivotally connected toa link 23 which is also pivotally connected to the vehicle by a pin 25adjacent a pivotal connection 24 between the lift arm and vehicle. Ahydraulic cylinder 26 for controlling the title position of the bucketis pivotally connected between each forward tilt lever 16 and therespective bell crank member 19. A hydraulic cylinder 27 for controllingthe elevated position of the bucket is positioned for interactionbetween the vehicle and each of the bucket lift arms. The bucket loaderoperator controls extension or detail below) tend toward a hold positionto prevent movement or the bucket. However, both control systems areprovided with detents to permit the operator to set the control systemfor a preferred motion of the bucket with the control system temporarilylocked into its corresponding position by one of the detents. Referringagain to FIG. I particularly, a master valve 31 is associated with thelift jack control system and interacts with kickout cams 32 and 33 whenthe bucket is at ground level or dumping height respectively to causethe lift jack control system to be released from its detent position,whereupon the control system returns to its hold position and the bucketis prevented from further movement by means of the lift arms. The bucket12 of FIG. 1 is shown at ground level in a loading position while thebucket illustrated in phantom at 34 is in a carry position at a suitableheight to permit dumping. Similarly, a master valve 36 is associatedwith the tilt jack control system and interacts with cam surfaces 37 and38 when the bucket is tilted to its loading positon or dumping positionrespectively, to cause the tilt jack control system to be released fromits detent position, whereupon the control system returns to its holdposition and the bucket is prevented from further motion.

In the present invention, the lift and tilt controls are hydraulicallyinterrelated such that the tilt control has operating precedence overthe lift control. When the bucket is in its loading position at groundlevel it is necessary after loading for the operator to regulate boththe tilt and lift controls to respectively rack-back the bucket to itscarry position and to raise the bucket for dumping. To permit theoperator to initially set both the tilt and lift control whilepreventing the kick-out function of the lift control during thepreferential rack-back of the bucket to its carry position, the liftcontrol kick-out cam 32 is collapsible to prevent its continued kick-outinteraction with the master valve 31. Further, it is to be noted thatwhen the operator racks-back the bucket to its carry position, themaster valve 36 remains in kick-out relation with the kick-out camsurface 37 as the bucket is raised to dump height (note the phantombucket at 34 in FIG. 1). To prevent continued kick-out relation betweenthe master valve 36 and the cam 37 when the operator sets the tiltcontrols for bucket dumping, the master valve 36 also comprises acollapsible feature which will be discussed in more detail below.

Referring now to FIG. 2, the lift control system 28 is generally similarto the mechanism described in U.S. Patent No. 3,211,310. A control valve41 receives hydraulic fluid through a conduit 44 by means of a pump 42from a reservoir 43. A spool 46 disposed for longitudinal motion in thecontrol valve 41 to control fluid flow through the control valve iscentered in a hold position indicated by the letter H, by means of aspring centering mechanism 47, whereupon no fluid flow is permitted tothe lift jacks and the bucket lift arms are prevented from moving. Thespool also has a raise position R whereat fluid from the inlet conduit44 passes through the control valve to a conduit 48 which communicateswith the head ends of the lift jacks to cause extension of the jacks andlifting of the bucket. The spool also has a bucket lowering position Lwhereat fluid entering the control, valve from the conduit 44 isdirected to a conduit 49 which communicates the fluid with the rod endsof the lift cylinders to cause retraction of the jacks and lowering ofthe bucket. The spool has a float position F whereat fluid in thecontrol valve is in communication with both of the conduits 48 and 49 sothat the bucket and lift arms will descend by gravity. A bell cranklever 51 has one end 52 pivotally connected to the spool and is providedat its distal end with detent cam surfaces 53 and 54. A roller 56mounted on a separate pivotal lever 57 normally rides on an end surface58 of the bell crank lever, for example, when the spool is in its holdposition. However, the lever 57 and the roller 56 are urged leftwardlyby a spring 59, connected to the lever so that, when the spool isshifted leftwardly into its raise position, the roller engages thedetent cam surface 54 and prevents the spool from being returned to itshold position. Similarly, as the spool is shifted rightwardly to itsfloat position, the roller engages the detent cam surface 53 tosimilarly prevent the spool from returning to its hold position.

To provide the kick-out function which releases the bell crank lever 51and the spool 46, from either detented position, a slave cylinder 61 isrelated therewith and is controlled by fluid communication from themaster valve 31 through a fluid conduit 62. The cylinder 61 has a spool63 reciprocably mounted therein with an extension 64 being pivotallysecured to the lever 57. When the roller on the level 57 is in detentrelation with either of the cam surfaces 53 and 54, the spool 63 isshifted leftwardly so that a space 66 between lands is in fluidcommunication with the conduit 62 from the master valve. The spool has afluid passage 67 communicating the space 66 with an end chamber 68between the end of the spool and the cylinder 61. Upon a kick-outfunction of the master valve (discussed in detail below), high pressurefluid is communicated to the slave valve through the conduit 62 so thatthe fluid enters the space 66. Flow of the fluid to drain through aconduit 69 is restricted at 71 and high pressure fluid is communicatedthrough passage 67 into the end chamber 68 causing the spool and thelever 57 to be shifted rightwardly against the spring 59. The rightwardmotion of the lever 57 causes the roller 56 to be disengaged from eitherof the detent cam surfaces 53 or 54, and the control valve spool 46 isreturned to its hold position by means of the spring assembly 47.

The master valve 31 which cooperates with either of the kick-out cams 32or 33 to provide the above noted kick-out function is also described inU.S. Patent 3,211,- 310. Briefly, high pressure hydraulic fluid isintroduced to the master valve 31 by means of a conduit 72 which is incommunication with the fluid conduit 48 for the lift cylinder. When alever 73 on the master valve is rotated clockwise to the positionillustrated in FIG. 2, by interaction of its roller 74 with either ofthe kick-out cams 32 or 33, high pressure fluid from conduit 72 ispermitted to pass through the master valve 31 into the conduit 62 to actupon the slave piston 61 and provide a kick-out function of the controlvalve as discussed above. To provide proper kick-out interaction betweenthe valve and kick-out earns, the master valve is affixed to the loaderstructure. The earns 32 and 33 are mounted on the tilt linkage 23 bymeans of a bracket 70 such that both cams rotate about the valve duringraising or lowering of the bucket on its lift arms. The cams 32 and 33are so positioned on the bracket that they contact the lever roller 74of the master valve when the bucket is respectively at ground level in aloading position or at a suitable dump height in carry position. Toinsure a constant supply of high pressure fluid in the conduit 72, sincesuch exists in conduit 48 only during raising of the bucket, anaccumulator 75 is also disposed in communication with conduit 72 with acheck valve 76 disposed across conduit 72 between the accumulator 75 andthe conduit 48. Thus, high pressure fluid existing in conduit 48 iscommunicated into conduit 72 and accumulator 75 so the high fluidpressure is maintained in conduit 72 by the accumulator and preventedfrom draining to the conduit 48 by means of the check valve.

The necessity for the collapsible character of the kickout cam 32 isreadily apparent from a brief review of the operating sequence of thebucket loader. During loading, the bucket is in the position illustratedin FIG. 1 and at the completion of loading it is necessary both torackback the bucket to its carry position (illustrated at phantom 34)and to energize the lift jack 27 to raise the bucket to its dump height.With the bucket in that position, the roller 74 of the master valve isin kick-out relation with the cam 32. If the operator were to initiallyactuate both the tilt and lift control valves at the same time, thekick-out function of the master valve 31 would return the control valvespool 46 to its hold position during the preferential operation of thetilt jacks in racking back the bucket to its carry position. Thus,according to the present invention, the cam 32 is collapsible and uponengagement of the roller 74 therewith, the lever 73 will be rotatedclockwise to provide kick-out fluid to the slave cylinder. However, thecontinued pressure of the roller 74 against the cam 32 causes a collapseor retraction of the cam to result in a counter clockwise rotation ofthe lever 73 and the flow of kick-out fluid to the slave cylinder 61 isterminated.

To describe this collapsing function of the cam 32, reference is had toFIG. 5 wherein the cam is illustrated in detail as a dash-pot assemblyhaving a cylinder 81 with a piston 82 disposed for longitudinal motiontherein. An extension 83 of the piston 82 has a cap 84 for kick-outengagement with the roller 74. The piston is urged outwardly by a spring86. The cylinder has a passage 87 communicating through a conduit 89with a fluid reservoir 88. The piston 82 has a passage 91 thereacrosswhich contains a restricting orifice 92. In operation, as the roller 74of the master valve comes in contact with the cap 84, the restrictingorifice prevents rapid flow of hydraulic fluid from the spring chamberwith the result that the master valve lever is rotated clockwise toresult in the desired kick-out function. However, as the pressure of theroller 74 continues to be exerted against the cap,

hydraulic fluid in the cylinder spring chamber gradually flows throughthe restricting orifice permitting the piston 82, the extension 83 andthe cap 84 to move downwardly into the cylinder 81. As the cap movesdownwardly, the master valve lever 73 rotates counter clockwise to shutoff fluid communication to the slave cylinder and prevent subsequentfunctioning of the kick-out. After the bucket has been raised from itsground position, the lever roller 74 is no longer aligned with the capand the spring 86 causes outward movement of the piston cap, to interactwith the roller 74 during a subsequent loading cycle to commence thedesired kick-out.

Referring now to FIG. 3, the tilt jack control system 29 has a controlvalve 41, bell crank lever 51', lever 57 and slave cylinder 61' whichare similar to the components numbered 41, 51, 57 and 61 in the liftjack control system 28 of FIG. 2. An important difference is to be notedin the spool 46' of the control valve which is similarly centered by aspring mechanism 47 at a hold position H where no fluid flow ispermitted through the control valve to the tilt jacks thus preventingtilting motion of the bucket. The spool may be shifted leftwardly into arack-back position indicated at R where high pressure fluid in thecontrol valve from the conduit 44' is communicated to the rod end of thetilt jack 26 by means of the conduit 48'. The spool may also be shiftedrightwardly to a dump position indicated by D where high pressure fluidin the control valve is communicated to the head end of the tilt jack 26by means of the conduit 49'. When the spool is moved into the rack-backor dump position, the roller 56' on the lever 57 engages either thedetent cam surface indicated at 54 or 53 respectively to temporarilyhold the spool in its shifted position. The slave cylinder 61' issimilar to the slave cylinder 61 of FIG. 2 and operates according to theactuating kick-out fluid in conduit 62 to shift the lever 57'rightwardly, thus disengaging the roller 56' from either of the detentcarn surfaces and permitting the spool to return to its center holdposition according to the spring 47'. High pressure hydraulic fluid issimilarly assured at the master valve 36 by the fluid accumulator 75'and the check valve 76' in the conduit 72 which communicates the conduit48 with the master valve 36.

However, the construction of the master valve 36 and its method ofinteracting with the kick-out cam 37 and 38 varies from that describedwith reference to the lift control system of FIG. 2. As in FIG. 4, themaster valve 36 consists of a housing 101 having a spool 102reciprocably mounted therein and urged downwardly by means of a spring103. The housing has an inlet port 104 communicating the conduit 72'with an annular recess 106 and an outlet port 107 communicating theconduit 62' with an annular recess 108. The spool 102 has a land 109between a first annular slot 111 and a second annular slot 112. Thespool 102 is actuated by a lever 113 secured to a shaft 114 whichextends through the housing to have an external lever 116 securedthereto.

When the lever 116 is in the position illustrated in FIG. 4, theposition of the spool 102 is controlled by the spring 103 to preventcommunication of the high pressure fluid in 72' to the slave cylinder61' by means of the conduit 62'. However, as the external lever 116 isrotated clockwise, it causes the lever 113 to drive the spool 102upwardly against the spring 103, thus placing the conduits 72' and 62'in fluid communication through the master valve housing by means of theannular slot 112 on the spool, such that actuating kick-out fluid isprovided to the slave cylinder 61' to permit its kick-out operation asdescribed above.

To describe the cooperation of the master valve 36 with the kick-outcams 37 and 38 which provides actuating kick-out fluid to the slavecylinder 61, having reference to both FIGS. 3 and 4, the master valve 36is mounted upon one of the hydraulic jacks 26 (see FIG. 3). The externalmaster valve lever 116 has a toggle 117 and with a roller 118 pivotallyconnected to a bifurcated area 119 of the lever 116. A leftward surfaceportion 121 of the upper end of the toggle is sharply angled to permitthe toggle and roller to be pivoted leftwardly to the positionillustrated in FIG. 4. However, the rightward surface portion 122 of theupper end of the toggle is generally normal to the toggle so that whenthe toggle and roller are pivoted rightwardly to the positionillustrated in FIG. 3, the toggle forms an extension of the lever 116whereupon the lever is actuated by contact with the kickout cams asdescribed below. A spring 123 urges the toggle into its rightwardlypivoted position as illustrated in FIG. 3.

Continuing with reference to FIG. 3, the kick-out cams 37 and 38 aredisposed upon a tubular member 126, which is aflixed to the rod 127 ofthe tilt jack 26 by a suitable connection indicated at 128. To guide thetubular member 126 during its travel along with the tilt jack rod, it isin telescoping relation with a rod 129 which is aflixed to the tilt jack26. Referring also to FIG. 1 for general reference, the kick-out cam 38is disposed at a generally rearward position on the tubular member 126so that a forward sloping surface 131 thereon comes into actuatingrelation with the roller 118 of the master valve lever 116 when the tiltjack 26 is extended to place the bucket in dump position. Similarly, thekick-out cam 37 is disposed generally forwardly upon the tubular member126 such that a sloping surface 132 thereon comes into actuatingrelation with the roller of the master valve lever 116 when the tiltjack is retracted to position the bucket in its loading positionillustrated in FIG. 1. However, as may be noted in FIG. 1, when theoperator racks-back the bucket from its loading position to a carryposition, the roller 118 rides forwardly upon the kick-out cam 37. Withfurther reference to FIG. 1, it may be noted that when the bucket isracked back to a carry position, the roller 118 rests upon the kick-outcam 37 at a point just in front of a folding latch arrangement 133 whichis disposed upon the kick-out cam 37. Due to the inter-connection of thetilt linkage between the bucket and the lift arms, the master valvelever roller remains in that position as the bucket is raised to itsdump height in carry position as illustrated by the phantom postion 34of FIG. 1. With the roller riding upon the cam surface, it is apparentthat when the operator positions the tilt control valve 41' to its dumpposition, the master valve would then remain in its actuating positionuntil the roller clears the cam 37, thus requiring the operator to holdthe control valve spool 46' in its dumping position until the rollercleared the cam 37. To permit the operator to merely place the tiltcontrol valve spool in its dumping position, with the spool autmaticallyheld in that position until the bucket is dumped, the latch mechanism133 (best illustrated in FIG. 4) has a pivotal latch 134 which trips thetoggle 117 and causes it to rotate leftwardly against the spring 123 asits roller 118 passes over the latch. The toggle, in its leftwardposition illustrated in FIG. 4, permits the master valve lever 116 torotate counter clockwise and the master valve terminates the flow ofactuating kick-out fluid to the slave cylinder 61.

To prevent the latch 134 from interfering with the toggle position asits roller 118 advances leftwardly thereacross, the latch is pivotallyconnected to the cam 37 by a pin 136 and has a spring 137 disposed forinteraction between the cam and the latch which tends to urge the latchrightwardly. Thus, as the roller advances leftwardly across the latch,the latch pivots leftwardly against the spring and into generalalignment with the upper surface of the cam so that it does notinterfere with the actuating position of the toggle 117 and the mastervalve lever 116. However, after the roller passes leftwardly across thelatch, the latch is erected to its position shown in FIG. 4 by thespring to permit its subsequent tripping interaction with the toggle asdescribed above.

The advantages of the present invention in reducing the manipulativeduties of the bucket loader operator, are readily apparent from aconsideration of the operating cycle of the bucket loader. For example,as the bucket approaches its loading position illustrated in FIG. 1, the"lift jack controls are detented in float position while the tilt jackcontrols are detented in rack-back position. When the bucket arrives atground level, the lever 73 ;of the master valve of the lift controlsystem interacts with the collapsible cam 32 and the master valveprovides (actuating kick-out fluid to the slave cylinder 61 to releasethe control valve spool 46 from its detented float position 'and permitit to return to its hold position, thus terminating operation of thelift jacks. Similarly, when rackback of the tilt jacks places the bucketin its proper loading position, the lever 116 of the master valve 36associated with the tilt control system engages the sloping surface 132of the kick-out cam 37 and the master "valve provides actuating kick-outfluid to the slave cylinder 61 which releases the tilt control valvespool 46' from its rack-back position and permits it to return to itshold position to terminate further tilting operation. With the bucket inits loading position, the operator drives the vehicle forwardly toengage the bucket with tnaterial to be loaded. The operator then placesthe lift control valve spool in its raise position and the tilt controlvalve spool in its rack-back position. The collapsible nature of cam 32prevents it from actuating the lift control master valve 31 thuspermitting the lift control valve spool to remain in its raisedposition. The operator continues to hold the tilt control valve spool inits rack-back position until the bucket has assumed a proper carryposition during which period the roller 118 on the tilt control mastervalve 36 rides leftwardly over the cam 37 and the latch 134. Theoperator releases the tilt control valve spool 46 with the bucket in itscarry position, whereupon the lift jacks continue to elevate the bucketto its dumping height illustrated by phantom position 34 in FIG. 1. Withthe vehicle properly positioned for dumping, the operator positions thetilt control valve spool in its dump position whereupon the toggle 117of the tilt control master valve is tripped by the erected latch 134,thus permitting the tilt control valve spool to remain in its dumpposition without further attention by the operator. As the kick-out cam37 moves leftwardly away from the roller 118 of the tilt control mastervalve 36, the spring 123 causes the toggle to rotate rightwardly. Thenwhen the bucket is in its dumping position, the toggle cooperates withthe master valve lever 116 and the sloping surface of the kick-out cam38 so that the master valve 36 provides actuating kick-out fluid to theslave cylinder 61' which releases the tilt control valve spool 46 fromits dumping position and terminates operation of the tilt control jacks.At this point, the operator repositions the lift control valve spool inits float position and the tilt control valve spool in its rack-backposition whereupon the bucket returns to its loading position at groundlevel as described above Without further attention from the operator anda new loading cycle may be commenced.

It is apparent from the above description that the manipulative dutiesof the operator are substantially reduced by the present invention. Forexample, when the operator desires to raise the bucket to its dumpingheight, to tilt the bucket forwardly for dumping, or to return thebucket to its loading position after dumping, it is only necessary forhim to initially position the control .valve spool after which he maydirect his attention to operation of the vehicle itself while the bucketmotion is terminated at the proper position. Further, particularly whenthe bucket loader is a very large vehicle, the operator is not requiredto direct his attention to the bucket to ensure that its motion isterminated at the proper position.

It is further to be noted that the operator can retain full manualcontrol over the tilt and lift controls by merely holding the controlvalve spools in a desired position whereupon the kick-outs will notfunction as described above.

We claim: 1. A bucket positioning kickout system for a bucket loaderhaving .a bucket suspended by lift arms, tilt means for controlling thetilt position of the bucket and lift means for controlling bucketelevation through the lift ,arms, the tilt means and lift means tendingtoward hold positions to prevent tilt or lift motion of the bucket andhaving detent means for temporarily holding the tilt and lift controlmeans in various operative positions, the combination comprising:

first and second tilt control kickout means arranged for interactionwith the tilt control means when the bucket is properly tilted forloading and dumping respectively to release the tilt control means froma detented condition,

first and second lift control kickout means arranged for interactionwith the lift control means when the bucket is at a proper elevation forloading and dumping respectively to release the lift control means froma detented condition, the tilt control means having operating preferenceover the lift control means, and

means for terminating effective interaction of the first lift controlkickout means following initial interaction therebetween to preventsubsequent kickout interaction of the first lift control kickout meansprior to subsequent motion of the bucket on its lift arms, saidterminating means permitting similar interaction between the first liftcontrol kickout means and the lift control means thereafter.

2. The combination of claim 1 wherein all of said kickout means may beoverridden to permit completely manual positioning of the bucket by anoperator of the loader.

3. The combination of claim 1 wherein the lift control kickoutterminating means is an element in the first lift control kickout meanswhich is collapsible following its interaction with the lift controlmeans, the collapsible element being self restoring after subsequentmotion of the bucket on its lift arms.

4. The combination of claim 3 wherein said first tilt control kickoutremains in kickout interaction with said tilt control means duringrack-back of the bucket from its loading position to its carry positionand means are operatively associated with said first tilt controlkickout to terminate its kickout interaction with said tilt controlmeans upon forward tilting of the bucket from its carry position, saidkickout terminating means being selfrestoring thereafter to permitkickout interaction between said first tilt control kickout and saidtilt control means when the bucket subsequently is tilted to its loadingposition.

5. The combination of claim 4 wherein said lift control means comprisesat least one hydraulic motor disposed in controlling relation to thebucket lift arms, a lift control valve operatively associated with saidhydraulic motor for controlling its operation, said control valvetending to be in a hold position but operable at least into detentpositions whereat said motor raises or permits lowering of the bucket onits lift arms, slave means associated with said control valve andoperable according to kickout fluid provided therein to release saidcontrol valve from its detented positions and a master valve in fluidcommunication with said lift control slave means, said master valveoperable to direct kickout fluid to said lift control means upon itsinteraction with said lift control kickout means.

6. The combination of claim 5 wherein said lift control master valve hasa lever for controlling its operation and said first and second liftcontrol kickout means are cams disposed on a loader member for motionrelative to said lift control master valve lever according to motion ofthe bucket lift arms.

7. The combination of claim 6 wherein said first kickout cam is adashpot assembly having a movable piston and a piston rod extending fromsaid assembly for interacting contact with said master valve lever.

8. The combination of claim 4 wherein said tilt control means comprisesat least one hydraulic motor asso ciated with the bucket by means oftilt linkage, a tilt control valve operatively associated with said tiltmotor -for controlling its operation, said tilt control valve tending tobe in a hold position while being operable into detent positions Whereatsaid tilt motor tilts the bucket forwardly and rearwardly by means ofits tilt linkage, tilt control slave means associated with said tiltcontrol valve and operable according to kickout fluid provided thereinto release said tilt control valve from its detented positions and atilt control master valve in fluid communication with said tilt controlslave means, said master valve operable to direct kickout fluid to saidtilt control slave means upon its interaction with said tilt controlkickout means.

9. The combination of claim 8 where the tilt control motor is ahydraulic jack having a cylinder and rod and wherein said tilt controlmaster valve has a rotatable lever for controlling its operation and ismounted on the jack cylinder and said tilt control kickouts are camsmounted on a member connected to the jack rod for motion therewith tomove said kickout cams into interacting relation with said tilt controlmaster valve lever for operation of said tilt control master valve.

10. The combination of claim 9 wherein said tilt control master valvelever has a pivotal toggle tending toward a centered position tocooperate with said tilt control lever and wherein said first tiltkickout cam has an elongated surface for interaction with said tiltcontrol lever by means of its pivotal toggle and a folding latchdisposed on its elongated surface which permits the toggle to ridethereover in its centered position as the bucket is tilted rearwardlyfrom its loading position to its carry position but which trips saidtoggle from its centered position to prevent its cooperation with thetilt control lever in providing for kickout operation of the tiltcontrol master valve as the bucket is tilted forwardly from its carryposition.

References Cited UNITED STATES PATENTS 3,122,247 2/1964 Beck 2147643,211,310 10/1965 McIndoo 214764 HUGO O. SCHULZ, Primary Examiner.

US. Cl. X.R.

